The invention relates generally to the detection of contraband located within articles. More particularly, the invention relates to the detection of objects considered illegal for transport that are hidden in luggage or mail parcels.
There has been and continues to be a demand for heightened security measures surrounding various communication and transportation avenues. For example, metal detectors and x-ray machines are standard security devices employed at airports for screening passengers and their carry-on luggage. The United States Postal Service also employs x-ray technology for screening parcels for mailing.
The capability for automatically screening luggage in a sufficiently efficient and cost-effective manner is currently non-existent. The screening systems currently in place record false positives at higher than desirable rates. The high number of false positives forces alternative follow-on inspections, such as trace detection or manual inspection of the luggage, thereby increasing the average screening time per bag substantially. There remains a need for a high throughput (e.g., at least one-thousand scanned checked bags per hour) automatic screening system for ascertaining whether a piece of luggage or a mail parcel contains an object which may be harmful, such as, for example, an explosive device or material.